Johns Hopkins researchers investigate mechanisms behind muscle growth

Individuals who regularly hit the gym in an effort to build muscle often see the results in the form of bulky biceps and ripped abs. Now, a team of scientists at Johns Hopkins University know exactly what happens during muscle growth on a cellular level.

During muscle development, the cytoskeleton from a muscle cell builds projections that resemble tiny fingers. These extensions then reach out into another muscle cell and fuse to it, creating a merge between the two cells.

However, some muscle cells contain a protein that scientists call "Blown Fuse," which prevents the cells from fusing.

“Blown Fuse was found to play a role in muscle cell fusion 14 years ago,” said co-author Elizabeth Chen. “And now we know how Blown Fuse regulates the dynamics of the cytoskeleton to facilitate the invasion of one muscle cell by another.”

The protein was shown to disrupt a complex formed by another essential protein pair, called WASP-WIP, that regulates muscle cytoskeleton. Blown Fuse causes the finger-like projections that would normally reach out to fuse with other cells to become limp and inactive, thereby hindering muscle growth.

The researchers speculated that stabilizing WASP-WIP may be a useful mechanism to regulate the dynamics of the muscle cytoskeleton.